I just finished working on a really big project in which I needed to produce paper copies of a few of my patterns. While we were at Ikea last week I found the perfect paper to use: their Mala drawing paper. It's a nice weight--much heavier than traditional pattern paper, but not as dense as card stock--and it's pretty cheap too. The roll of 30 meters was only $4.99. Can't beat that. I'm pretty sure it's not acid-free, but that wasn't necessary for what my project.
I have my master pattern pieces on a lightweight, flexible plastic material, so I just traced them onto the paper with a Sharpie marker, using my handy metal washers as weights.
I was able to use a rotary cutter to cut the straight portions of my patterns out, and then I finished the rest with a pair of scissors.
I needed to mail my pattern pieces, and the Mala paper patterns rolled up really nicely and were able to be shipped in a cardboard tube. I also think the paper would work well for applique patterns, quilt patterns and diagrams, and even paper piecing.